Detection device

ABSTRACT

This detection device is provided with: a chip including a detection region for detecting a substance to be detected; a light source which emits excitation light; a detector for detecting the fluorescence emitted from a fluorescent substance which labels the substance to be detected, and which is excited by the excitation light; and an optical fiber which includes a core, and a cladding covering the outer peripheral surface of the core, guides, to the detection region, the excitation light emitted from the light source, and guides, to the detector, the fluorescence emitted from the fluorescent substance. The optical fiber is fixed to the chip directly or via a connector. The excitation light emitted from the light source is guided within the core, and reaches the detection region of the chip. The fluorescence emitted from the fluorescent substance is guided within the core and the cladding, and reaches the detector.

TECHNICAL FIELD

The present invention relates to a detection apparatus which detects adetection object substance by detecting fluorescence emitted from afluorescence material labelling the detection object substance.

BACKGROUND ART

In recent years, in the field of food tests, laboratory tests,environment tests and the like, analysis of trace detection objectsubstances such as protein and nucleic acid is performed. For detectionof these detection object substances, detection apparatuses which canquantitatively detect the detection object substances with highsensitivity are used.

A known example of the detection apparatuses which can detect adetection object substance with high sensitivity is an apparatus whichutilizes fluorescence emitted from a fluorescence material labelling adetection object substance (see, for example, PTL 1).

The detection apparatus disclosed in PTL 1 includes a light sourcesection, a chip and a detection section. The light source section isdisposed above the chip, and the detection section is disposed below thechip with a space therebetween.

The light source section includes an optical fiber, a rod lens disposedat one end portion of the optical fiber, and a light source which isoptically connected with the other of end portion of the optical fiberand configured to emit excitation light. In addition, the chip includesa channel in which a capturing body capturing a detection objectsubstance labeled by a fluorescence material is disposed. In addition,the chip does not allow excitation light to pass therethrough. Thedetection section includes a sensor and a computer connected with thesensor.

In the detection apparatus disclosed in PTL 1, excitation light sent bythe optical fiber is applied toward the chip (fluorescence material)through the rod lens. The fluorescence material irradiated with theexcitation light is excited, and emits fluorescence. At this time, thechip does not allow the excitation light to pass therethrough, and thusonly fluorescence reaches the sensor.

CITATION LIST Patent Literature PTL 1 Japanese Patent ApplicationLaid-Open No. 2003-302360 SUMMARY OF INVENTION Technical Problem

However, in the detection apparatus disclosed in PTL 1, the sensor fordetecting radially emitted fluorescence is disposed below the chip witha space therebetween. Consequently, disadvantageously, fluorescenceemitted in directions other than the direction of the detection sectioncannot be detected, and sufficient detection sensitivity cannot beobtained. In addition, since the optical fiber and the sensor areseparated from the chip with a space therebetween, optical axisalignment at the time when excitation light is emitted toward the chip(fluorescence material) is difficult. When the optical axis alignmentcannot be appropriately performed, disadvantageously, sufficientdetection sensitivity cannot be obtained.

In view of this, an object of the present invention is to provide adetection apparatus which can detect fluorescence emitted from afluorescence material with high sensitivity and can readily performoptical axis alignment.

Solution to Problem

A detection apparatus according to embodiments of the present inventionincludes: a chip including a detection target region for detecting adetection object substance; a light source configured to emit excitationlight; a detector configured to detect fluorescence emitted from afluorescence material labelling the detection object substance andexcited with the excitation light; and an optical fiber including a coreand a clad which covers an outer peripheral surface of the core, theoptical fiber being configured to guide excitation light emitted fromthe light source to the detection target region, and guide fluorescenceemitted from the fluorescence material to the detector. The opticalfiber is directly fixed to the chip, or fixed to the chip through aconnector; the excitation light emitted from the light source is guidedin the core and reaches the detection target region of the chip; and thefluorescence emitted from the fluorescence material is guided in thecore and the clad and reaches the detector.

Advantageous Effects of Invention

The detection apparatus of the present invention can detect fluorescencewith high sensitivity without performing complicated optical axisalignment, and thus can readily detect a detection object substance withhigh sensitivity.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a configuration of a detection apparatus according toEmbodiment 1;

FIG. 2A to FIG. 2D illustrate a configuration of chip;

FIG. 3A and FIG. 3B illustrate a positional relationship between anoptical fiber and a chip;

FIG. 4A illustrates a part of light paths of excitation light in theoptical fiber part and FIG. 4B illustrates a part of light paths offluorescence in the optical fiber part;

FIG. 5A illustrates light paths of excitation light of an optical fiberpart of a modification of Embodiment 1, and FIG. 5B illustrates lightpaths of fluorescence in the optical fiber part;

FIG. 6A and FIG. 6B are sectional views illustrating anotherconfiguration of the optical fiber;

FIG. 7A to FIG. 7D illustrate a configuration of a chip according toEmbodiment 2;

FIG. 8A illustrates light paths of excitation light in an optical fiberpart according to Embodiment 2, and FIG. 8B illustrates light paths offluorescence in the optical fiber part; and

FIG. 9A to FIG. 9C are sectional views illustrating anotherconfiguration of the optical fiber.

DESCRIPTION OF EMBODIMENTS

In the following, embodiments of the present invention will be describedin detail with reference to the accompanying drawings.

Embodiment 1 Configuration of Detection Apparatus

The detection apparatus according to an embodiment of the presentinvention is an apparatus for detecting a detection object substance byirradiating a fluorescence material labelling a detection objectsubstance in a detection target region of a chip with excitation light,and detecting fluorescence emitted from the detection target region(fluorescence material).

FIG. 1 illustrates a configuration of detection apparatus 100 accordingto Embodiment 1 of the present invention. As illustrated in FIG. 1,detection apparatus 100 includes chip 140 including detection targetregion 149 for detecting a detection object substance, light source 120configured to emit excitation light, detector 160 configured to detectfluorescence emitted from a fluorescence material which labels adetection object substance and is excited with excitation light, opticalfiber 180 configured to guide excitation light emitted from light source120 to detection target region 149 and guide fluorescence emitted fromthe fluorescence material to detector 160, dichroic mirror 161configured to reflect the excitation light emitted from light source 120toward an end surface of optical fiber 180, and filter 162 configured toadjust the intensity of fluorescence.

Light source 120 emits excitation light for causing emission offluorescence from a fluorescence material. The type of the light sourceis not limited, and may be appropriately selected in accordance with thetype of the fluorescence material to be used and the like. Light source120 is, for example, a mercury lamp, a xenon lamp, an LED, a laser orthe like. In addition, light source 120 may include a filter whichallows predetermined excitation light to pass therethrough.

Detector 160 detects the fluorescence emitted from the fluorescencematerial. The type of detector 160 is not limited as long as thefluorescence can be detected. Examples of detector 160 include acharge-coupled device (CCD), a photomultiplier tube (PMT) and the like.

Dichroic mirror 161 reflects the excitation light emitted from lightsource 120 toward an end surface of optical fiber 180. In addition,dichroic mirror 161 allows the fluorescence emitted from the end surfaceof optical fiber 180 to pass therethrough.

Filter 162 blocks light having a wavelength other than that of thefluorescence which is incident on detector 160. Filter 162 is disposedbetween dichroic mirror 161 and detector 160. The fluorescence havingpassed through dichroic mirror 161 is adjusted by filter 162, andreaches detector 160.

On the light path of the excitation light from light source 120 to chip140, dichroic mirror 161 and optical fiber 180 are disposed in thisorder from light source 120 side. The excitation light emitted fromlight source 120 is reflected at dichroic mirror 161 toward an endsurface of optical fiber 180. The excitation light reflected by dichroicmirror 161 is applied to a detection target region (fluorescencematerial) of chip 140 through optical fiber 180. In addition, on thelight path of the fluorescence from chip 140 to detector 160, opticalfiber 180, dichroic mirror 161 and filter 162 are disposed in this orderfrom chip 140 side. The excitation light emitted from the fluorescencematerial (detection target region) passes through optical fiber 180,dichroic mirror 161 and filter 162, and reaches detector 160.

FIG. 2A to FIG. 2D illustrate a configuration of chip 140. FIG. 2A is aplan view of chip 140, FIG. 2B is a bottom view of chip 140, FIG. 2C isa sectional view taken along line A-A of FIG. 2A, and FIG. 2D is asectional view taken along line B-B of FIG. 2A.

As illustrated in FIG. 2, chip 140 is a device for flowing of a liquidsample. Chip 140 is composed of substrate 141 and film 142. Chip 140includes channel 143, sample inlet 144, sample outlet 145 and detectiontarget region 149. One end of channel 143 is communicated with sampleinlet 144. In addition, the other end of channel 143 is communicatedwith sample outlet 145. The number and installation position of channel143 are not limited. In the present embodiment, one channel 143 isdisposed. In addition, in the present embodiment, one sample inlet 144and one sample outlet 145 are disposed. The cross-sectional area and thecross-sectional shape of the channel in the direction orthogonal to thedirection of liquid flow are not limited. A sample introduced fromsample inlet 144 flows to sample outlet 145 through channel 143.

Detection target region 149 is a region of an internal surface ofchannel 143, and, in the present embodiment, is a region where acapturing body for capturing a detection object substance is fixed. Thecapturing body is disposed at a part of the bottom surface of channel143. The region where capturing body is disposed is detection targetregion 149. A detection object substance in a sample introduced fromsample inlet 144 is captured by the capturing body fixed in detectiontarget region 149 of channel 143. It is to be noted that a capturingbody may not be disposed in detection target region 149. That is, it isalso possible to adopt a configuration in which the detection objectsubstance labeled with the fluorescence material is detected indetection target region 149 in the course of flowing in channel 143.

Substrate 141 is a flat plate made of a resin including groove 146,first through hole 147 and second through hole 148. One end of groove146 is communicated with first through hole 147. In addition, the otherend of groove 146 is communicated with second through hole 148. When oneopening part of first through hole 147, an opening part of groove 146,and one opening part of second through hole 148 are sealed with film142, sample inlet 144, channel 143 and sample outlet 145 are formed. Thetype of the resin of substrate 141 is not limited as long as channel 143can be formed together with film 142, and may be appropriately selectedfrom publicly known resins. The examples of the resin of substrate 141include polyethylene terephthalate, polycarbonate,polymethylmethacrylate, vinyl chloride, polypropylene, polyether,polyethylene, polystyrene, silicone resin and the like.

Film 142 is a substantially rectangular transparent resin film. Film 142is bonded on one surface of substrate 141 on which groove 146 is opened.The way of bonding substrate 141 and film 142 is not limited, andsubstrate 141 and film 142 may be bonded by thermo compression bonding,for example. The type of the resin of film 142 is not limited as long aschannel 143 can be formed together with substrate 141, and theexcitation light and the fluorescence can pass therethrough. Preferably,the thickness of film 142 is small as much as possible in considerationof the type (rigidity) of the resin, the bonding property of film 142and the like. When film 142 having a large thickness is used, absorptionof detection light (fluorescence) in detection target region 149 isincreased, and a desired signal intensity cannot be obtained. In thepresent embodiment, film 142 has a thickness of about 20 μm.

FIG. 3A and FIG. 3B illustrate a positional relationship between opticalfiber 180 and chip 140. FIG. 3A is a sectional view of optical fiber 180and chip 140 along central axis CA of optical fiber 180 in the widthdirection of channel 143, and FIG. 3B is a sectional view of opticalfiber 180 in a direction orthogonal to central axis CA of optical fiber180. It is to be noted that, in FIG. 3A and FIG. 3B, substrate 141, film142 and channel 143 are illustrated with broken lines. FIG. 4A and FIG.4B illustrate light paths of optical fiber 180 in detection apparatus100. FIG. 4A illustrates a part of the light paths of excitation light,and FIG. 4B illustrates a part of light paths of fluorescence.

As illustrated in FIG. 4A and FIG. 4B, optical fiber 180 guides theexcitation light emitted from light source 120 to detection targetregion 149 (fluorescence material), and guides the fluorescence emittedfrom the fluorescence material toward detector 160. Optical fiber 180 isan optical transmission cable including core 181 and clad 182.Preferably, one end portion of optical fiber 180 is in contact with thesurface (film 142) of chip 140. With this configuration, thefluorescence emitted from the fluorescence material can be efficientlyguided toward detector 160, and the excitation light emitted from lightsource 120 can be efficiently applied to detection target region 149(fluorescence material).

Core 181 guides the excitation light emitted from light source 120 andreflected by dichroic mirror 161 to the fluorescence material ofdetection target region 149, and guides the fluorescence emitted fromthe fluorescence material toward detector 160. Core 181 is disposedalong central axis CA of optical fiber 180. In the direction orthogonalto central axis CA, core 181 has a circular cross-sectional shape. Inaddition, preferably, in the direction orthogonal to central axis CA,diameter d1 of core 181 is approximately equal to width d2 (detectiontarget region) of channel 143 (see FIG. 3A and FIG. 3B). When diameterd1 of core 181 in the direction orthogonal to central axis CA issignificantly small in comparison with width d2 of channel 143, theirradiation area of the excitation light applied to a fluorescencematerial is small, and consequently the excitation light cannot beuniformly applied. It should be noted that the excitation light emittedfrom an end portion of optical fiber 180 has a spread angle inaccordance with the numerical aperture (NA) of optical fiber 180 duringthe emission. Accordingly, diameter d1 of core 181 in the directionorthogonal to central axis CA may be set to a value slightly smallerthan width d2 of channel 143 in accordance with the distance from an endportion of core 181 to detection target region 149. On the other hand,when diameter d1 of core 181 in the direction orthogonal to central axisCA is significantly larger than width d2 of channel 143, the excitationlight which is not applied to the fluorescence material in theexcitation light emitted from light source 120 is wasted. It should benoted that for allowance of an error in accordance with the accuracy ofthe optical axis alignment, a value slightly larger than width d2 ofchannel 143 may be set. In this manner, diameter d1 of core 181 in thedirection orthogonal to central axis CA is set in accordance with widthd2 (detection target region) of channel 143. In the present embodiment,in the direction orthogonal to central axis CA, core 181 has a diameterof about 105 μm with respect to channel 143 having a width of 100 μm.Preferably, with respect to the width of channel 143, the diameter ofcore 181 is set to ±10%, and to about ±10 μm in the absolute value. Thematerial of core 181 is not limited as long as the excitation light andthe excitation light can pass therethrough. Examples of the material ofcore 181 include quartz, multicomponent glass, polymethyl methacrylate(PMMA) and the like.

Clad 182 is disposed on the outside of core 181 in such a manner as tocover the outer peripheral surface of core 181. The outer diameter ofclad 182 in the direction orthogonal to central axis CA is not limited.The outer diameter of clad 182 in the direction orthogonal to centralaxis CA is about 100 μm to 2 mm That is, the thickness of clad 182 inthe direction orthogonal to central axis CA is about 25 to 975 μm. Thekind of the material of the clad is not limited as long as theexcitation light can pass therethrough. Examples of the material of clad182 include quartz, multicomponent glass, silicone resin and the like.In particular, preferably, the material of clad 182 has a refractiveindex lower than that of core 181, and has a refractive index higherthan that of the environment adjacent to the outer periphery of clad182, in view of guiding fluorescence emitted from the fluorescencematerial to detector 160.

As illustrated in FIG. 4A, the excitation light emitted from lightsource 120 is reflected by dichroic mirror 161, and emitted toward chip140 (fluorescence material) through core 181. The excitation lightemitted toward chip 140 passes through film 142, and is applied to afluorescence material disposed in detection target region 149. Asillustrated in FIG. 4B, in the fluorescence emitted from thefluorescence material labelling a detection object substance which iscaptured by a capturing body of detection target region 149,fluorescence having a small angle relative to the central axis ofoptical fiber 180 is incident on core 181 through film 142. The lightincident on core 181 is guided to detector 160 through dichroic mirror161 and filter 162 via through core 181. In addition, the fluorescencehaving a large angle relative to the central axis of optical fiber 180is incident on core 181 and clad 182 through film 142. The lightincident on core 181 is guided to detector 160 through dichroic mirror161 and filter 162 via core 181 and clad 182.

(Effect)

As described above, in detection apparatus 100 according to the presentembodiment, an end portion of optical fiber 180 on detection targetregion 149 side is adjacent to chip 140 (film 142), and the excitationlight emitted from light source 120 is guided to chip 140 (fluorescencematerial) with core 181 of optical fiber 180 whereas the fluorescenceemitted from the fluorescence material is guided to detector 160 withcore 181 of optical fiber 180 and clad 182. Accordingly, detectionapparatus 100 can detect the fluorescence emitted from the fluorescencematerial with high sensitivity.

[Modification]

A detection apparatus according to a modification of Embodiment 1 isdifferent from detection apparatus 100 according to Embodiment 1 in theconfiguration of optical fiber 180. Therefore, the components same asthose of detection apparatus 100 according to Embodiment 1 are denotedwith the same reference numerals and the description thereof is omitted,and, components different from detection apparatus 100 are mainlydescribed below.

(Configuration of Detection Apparatus)

FIG. 5A and FIG. 5B illustrate light paths of optical fiber 180 indetection apparatus 100. FIG. 5A illustrates a part of light paths ofexcitation light, and FIG. 5B illustrates a part of light paths offluorescence.

As illustrated in FIG. 5A and FIG. 5B, optical fiber 180 includes core181 and clad 182. Core 181 has a configuration similar to that ofEmbodiment 1. In the present modification, it is preferable to set thethickness of clad 182 in the direction orthogonal to central axis CA toa large value as much as possible in view of efficiently causingincidence of detection light into clad 182. However, in a case wherechip 140 is to be downsized, or a case where a plurality of channels 143adjacent to each other are formed, the thickness of clad 182 is limitedin view of the distance between channels 143. To be more specific, inthe present modification, the thickness of clad 182 in the directionorthogonal to central axis CA is about four to five times the maximumdiameter of core 181.

As illustrated in FIG. 5A, the excitation light emitted from lightsource 120 is reflected by dichroic mirror 161, and emitted toward chip140 (fluorescence material) through core 181. The excitation lightemitted toward chip 140 is applied to the fluorescence material disposedin the detection target region through film 142. As illustrated in FIG.5B, in the fluorescence emitted from the fluorescence material labellingthe detection object substance which is captured by the capturing bodyof detection target region 149, the fluorescence having a small anglerelative to the central axis of optical fiber 180 is incident on core181 through film 142. The light incident on core 181 is guided todetector 160 through dichroic mirror 161 and filter 162 via through core181. In addition, the fluorescence having a large angle relative to thecentral axis of optical fiber 180 is incident on core 181 through film142. The light incident on core 181 is guided to detector 160 throughdichroic mirror 161 and filter 162 via core 181 and clad 182. Further,the fluorescence having a significantly large angle to the central axisof optical fiber 180 is incident on clad 182 through substrate 141 andfilm 142. The light incident on clad 182 is guided to detector 160through dichroic mirror 161 and filter 162 via core 181 and clad 182.

(Effect)

As described above, in the detection apparatus according to themodification of Embodiment 1, the thickness of clad 182 of optical fiber180 is large relative to the diameter of core 181 of optical fiber 180.Consequently, in the fluorescence emitted from the fluorescencematerial, the fluorescence having a large angle relative to the centralaxis of optical fiber 180 can also be guided to detector 160 (see FIG.5A and FIG. 5B). Thus, detection sensitivity can be further increased incomparison with detection apparatus 100 of Embodiment 1.

It is to be noted that, as illustrated in FIG. 6A and FIG. 6B, opticalfiber 180 may be fixed to chip 140 with ferrule (connector) 183. In thiscase, engagement hole 184 for engaging an tip end portion of ferrule 183is disposed in chip 140. With this configuration, optical fiber 180 canbe appropriately fixed to chip 140 (detection target region 149), and asa result, ease of alignment of the optical axis of optical fiber 180 indetection target region 149 can be increased. In addition, chip 140 maybe provided with a fitting part for fixing optical fiber 180 to fixoptical fiber 180 to chip 140 without interposing ferrule 183therebetween.

Embodiment 2

A detection apparatus according to a modification of Embodiment 2 isdifferent from detection apparatus 100 according to Embodiment 1 in theconfigurations of chip 240 and optical fiber 280. Therefore, thecomponents same as those of detection apparatus 100 according toEmbodiment 1 are denoted with the same reference numerals anddescription thereof is omitted, and, components different from those ofdetection apparatus 100 are mainly described below.

(Configuration of Detection Apparatus)

FIG. 7A to FIG. 7D illustrate a configuration of chip 240 according toEmbodiment 2. FIG. 7A is a plan view of chip 240, FIG. 7B is a bottomview chip 240, FIG. 7C is a sectional view taken along line C-C of FIG.7A, and FIG. 7D is a sectional view taken along line D-D of FIG. 7B.FIG. 8A and FIG. 8B illustrate light paths of optical fiber 280 in thedetection apparatus. FIG. 8A illustrates a part of light paths ofexcitation light, and FIG. 8B illustrates a part of light paths offluorescence.

As illustrated in FIG. 7A to FIG. 7D, chip 240 is composed of substrate241 and film 142. Chip 240 includes two recesses 250 in addition tochannel 143, sample inlet 144, and sample outlet 145.

Recesses 250 are holes for fitting an end of optical fiber 280. Recesses250 are opposed to each other with channel 143 therebetween. The shapeof recesses 250 is not limited as long as the tip end portion of opticalfiber 280 can be fitted. In the present embodiment, the bottom surfaceis formed in a semicircular columnar shape.

As illustrated in FIG. 8A and FIG. 8B, optical fiber 280 includes core181 and clad 282. At the end portion of optical fiber 280 on detectiontarget region 149 side, the end of clad 282 protrudes to chip 240(detection target region) side over the end of core 181. To be morespecific, in a cross-section which includes the central axis of opticalfiber 280 and which is taken along the liquid flow direction, the end ofclad 282 is flush with the end surface of core 181. On the other hand,in a cross-section which includes the central axis of optical fiber 280and is taken along a direction orthogonal to the liquid flow direction,the end of clad 282 protrudes over the end of core 181. In addition, ina cross-section taken along a direction orthogonal to the liquid flowdirection, an outer peripheral surface of the tip end portion of clad282 is a curved line protruding outward for guiding fluorescence to theend portion of optical fiber 280 on detector 160 side.

(Effect)

As described above, in the detection apparatus according to Embodiment2, the end surface of clad 282 of optical fiber 280 protrudes to chip240 side over the end surface of core 181. Consequently, in thefluorescence emitted from the fluorescence material, the fluorescencehaving a further large angle relative to the central axis of opticalfiber 280 can also be guided to detector 160 (see FIG. 4B, FIG. 5B andFIG. 8B). Thus, detection sensitivity can be further increased incomparison with detection apparatus 100 of Embodiment 1.

It is to be noted that as illustrated in FIG. 9A to FIG. 9C, reflectionfilm 285 as a reflection member for reflecting the fluorescence may beformed on the outer peripheral surface of clad 182 or 282. In this case,normally, reflection film 285 is formed over the entirety of the outerperipheral surface although reflection film 285 may be formed only at apart of the outer peripheral surface. The material of reflection film285 is not limited, and is a metal, for example. The way of formingreflection film 285 is not limited, and, for example, reflection film285 is formed by an evaporation method. The light (fluorescence) fromclad 182 or 282 side is reflected to clad 182 or 282 side by reflectionfilm 285.

In addition, core 181 may be shorter than the end of clad 182 or 282 ina cross-section including central axis CA of optical fiber 180 or 280and taken along the liquid flow direction such that a gap is formedbetween the surface of film 142 and core 181 when optical fiber 180 or280 is fixed to chip 140 or 240. In this case, optical fiber 180 or 280can be fixed to chip 140 or 240 without damaging the surface of film 142with the end portion of optical fiber 180 or 280 in detection targetregion 149.

Further, refractive index matching agent such as matching oil may beprovided in a gap between the surface of film 142 and core 181. In thiscase, fresnel reflection loss of detection light at an end portion ofcore 181 can be suppressed.

This application is entitled to and claims the benefit of JapanesePatent Application No. 2014-029475 filed on Feb. 19, 2014, thedisclosure each of which including the specification, drawings andabstract is incorporated herein by reference in its entirety.

INDUSTRIAL APPLICABILITY

The detection apparatus according to the embodiments of the presentinvention can detect fluorescence with high sensitivity, and thereforeis suitable for food tests, laboratory tests, environment tests, and thelike, for example.

REFERENCE SIGNS LIST

-   100 Detection apparatus-   120 Light source-   140, 240 Chip-   141, 241 Substrate-   142 Film-   143 Channel-   144 Sample inlet-   145 Sample outlet-   146 Groove-   147 First through hole-   148 Second through hole-   149 Detection target region-   160 Detector-   161 Dichroic mirror-   162 Filter-   180, 280 Optical fiber-   181 Core-   182, 282 Clad-   183 Ferrule-   184 Engagement hole-   250 Recess-   285 Reflection film

1. A detection apparatus comprising: a chip including a detection targetregion for detecting a detection object substance; a light sourceconfigured to emit excitation light; a detector configured to detectfluorescence emitted from a fluorescence material labelling thedetection object substance and excited with the excitation light; and anoptical fiber including a core and a clad which covers an outerperipheral surface of the core, the optical fiber being configured toguide excitation light emitted from the light source to the detectiontarget region, and guide fluorescence emitted from the fluorescencematerial to the detector, wherein: the optical fiber is directly fixedto the chip, or fixed to the chip through a connector; the excitationlight emitted from the light source is guided in the core and reachesthe detection target region of the chip; and the fluorescence emittedfrom the fluorescence material is guided in the core and the clad andreaches the detector.
 2. The detection apparatus according to claim 1,wherein, in a cross-section including an axis of the optical fiber, across-sectional width of the core falls within a range of ±10% of across-sectional width of the detection target region.
 3. The detectionapparatus according to claim 1, wherein a reflection member configuredto reflect light from the clad side to the clad side is disposed on anouter peripheral surface of the clad.
 4. The detection apparatusaccording to claim 1, wherein a tip end portion of the clad protrudesover a tip end portion of the core at an end portion of the opticalfiber on the detection target region side.
 5. The detection apparatusaccording to claim 4, wherein an outer peripheral surface of the tip endportion of the clad is a curved line protruding outward in thecross-section including the axis of the optical fiber.
 6. The detectionapparatus according to claim 4, wherein recesses capable of fitting thetip end portion of the clad is disposed around the object detectionregion of the chip.
 7. The detection apparatus according to claim 6,wherein: the detection target region is a part of a channel which isformed when a groove formed on the chip is sealed with a film; and therecesses are opposed to each other with the channel therebetween.
 8. Thedetection apparatus according to claim 1, wherein the optical fiber isfixed to the chip through the connector.